I'm more in favor of tackling the Moon first. An order of magnitude easier and cheaper and bootstraps the Mars process by mining ice/fuel components. We also will want a space elevator on both Moon/Mars. It makes sense to work out the logistics on a smaller and closer scale first at Luna.
[Spoken as a card carrying member of NSS and Moon Society and Board member of local dual accreditation chapter]
Why would we want to go through the work of crawling out of Earth's gravity well, only to crawl into one only a little bit shallower as a stepping stone to somewhere else? I'm not aware of siginificant fuel/mineral reserves on the moon, or am I mistaken on that?
I've been following this since the first press conference. I believe the idea is that the moon will work as a place to test technologies, tourism, and to serve as a general scientific base more than anything. You can only go to Mars reasonably every two years (and it takes months of travel), you can go to the moon pretty much as needed (in a couple of days), that's why the moon is important. We need a place with lower gravity, without a magnetosphere, with adverse environmental conditions to test things like how to setup the planned fuel depots, habitats, sun radiation protection, etc. for long term human survival on Mars without the expense and time of actually going to Mars.
For those of us that don't wish our headstones to be on the red planet (or to have our ashes scattered violently and unexpectedly on Mars), going for a trip to the moon will be both more realistic and "affordable". If it costs $200k to get to Mars one-way, and $200k to go to the moon-and-back for a couple of weeks, I could see a lot of wealthy people putting "trip to the moon" on their bucket lists and actually going through with it (as in a few thousand people a year going into space, instead of one or two like current space tourism). If you're performing space related research, it will make performing observation and research directly similar in cost and scale to what an Arctic expedition is today.
If Elon can Henry Ford the space industry, I'm all for it.